Work-supporting device

ABSTRACT

A lightweight, high-strength work rack for supporting one or a plurality of workpieces for transfer through an electrochemical treatment having a frame including a composite electrically conductive bar consisting of an aluminum core enclosed within and disposed in electrical contact with an exterior copper sleeve.

United States Patent Inventors Richard J. Jessup Bloomfield Hills; Richard T. Wigginton, Jr., Detroit, both of Mich. Appl. No. 751,226 Filed Aug. 8, 1968 Patented Dec. 7, 1971 Assignee The Udyllte Corporation WORK-SUPPORTING DEVICE 9 Cllillll, 9 Drawing Figs.

US. Cl. 204/297, 204/286, 204/290 Int. Cl C23b 5/70, B0 1 k 3/04 Field of Search 204/297,

[56] References Cited UNITED STATES PATENTS 647,858 4/1900 Mies 204/33 1,387,426 8/1921 Merritt... 204/33 X 1,515,658 11/1924 Cole 204/33 X 2,852,463 9/1958 Gutzmer 204/242 Primary Examiner-John H. Mack Assistant ExaminerA. C. Prescott Attorneys-Peter F. Cosella and Richard P. Mueller ABSTRACT: A lightweight, high-strength work rack for supporting one or a plurality of workpieces for transfer through an electrochemical treatment having a frame including a composite electrically conductive bar consisting of an aluminum core enclosed within and disposed in electrical contact with an exterior copper sleeve.

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SHEET 2 OF 2 NVENTORS. iza/drd Jamal v WORK-SUPPORTING DEVICE BACKGROUND OF THE INVENTION Work-supporting devices of the type to which the present invention is applicable are in widespread commercial use for supporting one or more workpieces or work racks during their transfer and processing in one or a series of treating stations. Work-supporting devices of this type find particular use in the electrochemical treatment of workpieces such as in electroplating operations, for example. There has been a continuing problem in providing such work-supporting devices which are of adequate strength so as to support the load of the workpieces to be processed while also being of sufficient electrical conductivity to assure proper electrification of the workpieces at such stations where an electrochemical treatment thereof is to be performed. Due to the corrosive environment in which such work-supporting devices are conventionally used, it is also necessary that they be of adequate corrosion resistance to avoid deterioration, as well as of high physical strength to avoid damage and/or deformation thereof by automatic work transfer mechanisms. It is also an important feature of such work-supporting devices that they be of light weight in order that they can be handled by automatic transfer equipment that is not unduly cumbersome and expensive.

The work supporting device of the present invention overcomes the problems and deficiencies of work-supporting devices of the types heretofore known by providing a highstrength, lightweight framework possessing good corrosion resistance and excellent electrical conductivity on which one or a plurality of workpieces can be supported during a processing cycle, as well as during transfer between work stations.

SUMMARY OF THE INVENTION The benefits and advantages of the present invention are achieved by a work-supporting device comprising a frame which includes an elongated bar of a composite construction consisting of a core of aluminum having a sleeve of copper extending therearound and disposed in supported and in electrical contact with the peripheral portions of the core. The frame further includes a supporting framework mounted on an in electrical contact with the bar on which one or more of the workpieces are removably mounted. Suitable contact means are affixed preferably to the end portions of the frame, which are adapted to be disposed in electrical contact with a source of electrical energy for effecting an electrification of the workpieces when the work-supporting device is disposed at a work station at which an electrochemical treatment is to be performed. Engaging members are also mounted on the frame for facilitating engagement of the supporting device by a transfer mechanism for conveying the work-supporting device and workpieces thereon from one work station to the next work station.

Other advantages and benefits of the present invention will become apparent upon a reading of the description of the preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a transverse elevational view, partly in section, illustrating a work-supporting device constructed in accordance with the preferred embodiments of the present invention disposed at a typical work station and a transfer mechanism for conveying the work-supporting device and workpieces supported thereon between such stations;

FIG. 2 is a transverse vertical sectional view through the work-supporting device shown in FIG. 1, and taken substantially along the line 2-2 thereof;

FIG. 3 is a transverse vertical sectional view through the work-supporting device shown in FIG. I, and taken substantially along the line 3-3 thereof;

FIG. 4 is a fragmentary side elevational view of the end portion of the work-supporting device supported by a contact saddle as viewed generally along the line 4-4 of FIG. 1;

FIG. 5 is an enlarged cross-sectional view of a typical construction of the composite bar of the framework of the work supporting device;

FIG. 6 is an alternative construction of the composite bar of the work-supporting device;

FIG. 7 is another alternative embodiment of the construction of the composite bar of the work-supporting device;

FIG. 8 is still another alternative embodiment of a construction of the composite bar of the work-supporting device; and

FIG. 9 is yet still another transverse cross-sectional view of an alternative satisfactory construction of the composite bar of the work-supporting device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawings and as may be best seen in FIG. I, a typical work station is illustrated applicable for use with a work-supporting device comprising the present invention. As shown in FIG. I, a treating receptacle 10 is mounted on a base for supporting platform 12 and is filled with a suitable treating solution, such as an electroplating solution 14, in which work racks or workpieces, typified by the rectangular panels 16, are adapted to be immersed. On the upper flanged edges of the treating receptacle 10, a supporting device or saddle 18 is securely mounted which is adapted to receive and support the end portions of a work-supporting device 20 when positioned at that treating station.

The work-supporting device 20 is comprised of a frame including an elongated transversely extending bar 22, on which connecting members 24 are affixed at longitudinally spaced points therealong, and to the lower ends of which a mounting bar 26 is securely fastened. The work racks or workpieces 16, as illustrated in FIG. 1, are provided with hook-shaped members 28, which are adapted to be engaged along the mounting bar 26 for suspending the workpieces therefrom. It will be understood that the workpieces I6, as illustrated in FIG. I, may themselves comprise an individual work rack on which one or a plurality of workpieces are mounted in electrical contact therewith.

The work-supporting device 20 is adapted to be transferred by a suitable manual or automatically operated transfer mechanism, such as the mechanism illustrated in FIG. I, including a pair of overhead rails 30 of an I-shaped cross section on which a carriage 32, having rollers 34, is movable mounted. The carriage is provided with a suitable lift member 36, which, in the typical embodiment illustrated, is provided with opposed outwardly extending engaging arms 38 that are adapted to engage engaging members 40 secured to the bar 22 for raising and lowering the work-supporting device between a lowered position, as illustrated in solid lines in FIG. 1, and a raised position, as shown in phantom. Suitable elevator means (not shown) are incorporated on the carriage 32 for effecting up and down movement of the lift member 36 and the engaging arms 38 thereon between the raised and lowered positions. Control of the vertical movement of the lift member 36 can be achieved automatically or manually such as by means of a switch 42 connected to the carriage which is manually operated by an operator to provide the desired operating sequence.

In accordance with the typical arrangement illustrated in FIG. I, the carriage 32 of the transfer mechanism is operative to travel along the rails 30, which usually extend along an aligned series of treating stations, effecting a successive transfer of the work-supporting devices 20 from one station to the next station, at which the workpieces are subjected to an electrochemical or other treatment for a prescribed dwell period. During such transfer movements of the carriage, worksupporting devices containing workpieces are ordinarily transferred over and drip upon work-supporting devices disposed in the lowered position at adjacent stations which, in combination with the corrosive environment, has been responsible for a physical deterioration of the work-supporting devices of the types heretofore known. In addition, the composite lightweight and high-strength construction of the work-supporting device of thepresent invention enables greater useful loads of workpieces to be placed thereon for a given transfer mechanism capacity, thereby increasing the efficiency of operation.

The elongated bar 22 of the work-supporting device 20, as shown in FIGS. 1-4 and in the specific embodiment illustrated in FIG. 5, comprises a core 44 of aluminum, which is completely enclosed within an outer sleeve of copper 46, which is disposed in supported electrical contact around the periphery of the core 44. It will be understood that the term aluminum" and the term copper," as herein employed and as set forth in the subjoined claims, are intended to encompass the substantially pure form of these two metals, as well as aluminum-base and copper-base alloys thereof consisting predominantly of aluminum and copper, respectively. In accordance with this construction, the maximum benefits of each of these two materials are obtained while simultaneously overcoming their respective disadvantages, whereby the high strength, light weight and low cost of the aluminum is maximized and the good corrosion resistance and good electrical contact of the copper with the saddles l8 and ancillary components on the work-supporting device are achieved. In accordance with the embodiment of the elongated bar 22, as illustrated in FIGS. 2-5 inclusive, the core 44 is of a circular cross section and is formed with a circular concentric central bore 48 extending substantially longitudinally through the length thereof. The surrounding copper sleeve 46 similarly is of a circular tubular configuration and is disposed in intimate supported contact around the entire periphery of the core 44. The provision of the central bore 48 contributes toward a further reduction in weight of the work-supporting device without any appreciable sacrifice in the strength thereof.

The peripheral portion of the sleeve 46 adjacent to each end portion thereof, as best seen in FIGS. 1 and 4, is clamped within a contact shoe 50 of an electrically conductive material, such as copper or a copper-base alloy, which is adapted to be slidably received within the tapered saddle 18 in a manner so that the opposed vertical side faces 52 are disposed in intimate electrical contact with the adjacent electrified bus bars 54 lining the inner portion of each saddle 18. The electrical current transferred to the contact shoe 50 is accordingly transmitted to the sleeve 46 and core 44 and passes therethrough to the connecting members 24 and thence to the mounting bar 26 on which the hook-shaped members 28 are disposed in electrical contact.

An alternative satisfactory construction of the elongated bar 22 is illustrated in FIGS. 6-9 of the drawings. As shown in FIG. 6, a core 56 of aluminum is provided, which is formed in a cross-shaped cross section having outer arcuate surfaces 58 defining the periphery thereof which are disposed in intimate electrical contact with the inner surface of a circular tubular copper sleeve 60.

In the arrangement as illustrated in FIG. 7, a core 62 of aluminum is provided which is of a substantially circular cross section and is formedwith a plurality of inwardly extending radial grooves 64, which are disposed at substantially equal circumferentially spaced increments and define a series of Iongitudinally extending arcuate surfaces or lands 66 which are disposed in supporting an intimate electrical contact with the inner surface of a surrounding circular tubular copper sleeve 68.

In the embodiment illustrated in FIG. 8, a central aluminum core 70 is provided which is formed with a plurality of longitudinally extending V-shaped grooves 72 of radially outwardly diverging configuration, defining therewith a plurality of Iongitudinally extending arcuate surfaces 74 disposed at substantially equal arcuate increments which are positioned in inti mate electrical and supporting contact with the inner surface of a circular tubular overlying copper sleeve 76.

In the embodiment as illustrated in FIG. 9, a core 78 of aluminum is formed with a series of V-shaped grooves 80 of an angularit soas to defineaplurality of radially extendin fins 82 Wl'llC are of substantially uniform thickness am? are disposed at substantially equal arcuate increments. The arcuate peripheral surface 84 of each of the fins 82 is disposed in intimate electrical and supporting contact with the inner surface of an encircling circular tubular copper sleeve 86. In each of the embodiments illustrated in FIGS. 5-9, the exposed ends of the elongated bars may be provided with an end cap, if desired, to seal the interior thereof from the surrounding atmosphere.

While it will be apparent that the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the fair meaning or proper scope of the subjoined claims.

What is claimed is:

1. In a work-supporting device for supporting a workpiece for conveyance through an electrochemical treatment in a treating receptacle, the improvement comprising a frame including a superior elongated bar extending transversely across and above said receptacle consisting of a core of aluminum and a sleeve of copper extending around said core and disposed in supported and electrical contact with the peripheral portions of said core, electrically conductive inferior work-supporting means spaced apart from said bar for removably supporting said workpiece, and electrically conductive spacing means electrically connecting said bar and said work-supporting means and maintaining said bar and said supporting means in fixed predetermined geometric relationship.

2. The work-supporting device as defined in claim I, further including engaging means on said frame adapted to be engaged for supporting and transporting said device between work stations.

3. The work-supporting device as defined in claim 1, further including contact means on said frame electrically connected to said bar and adapted to be disposed in electrical contact with a source of electrical energy at a work station.

4. The work-supporting device as defined in claim I, wherein said bar is of a substantially circular cross section and wherein said sleeve and said core are of a tubular configuration.

5. The work-supporting device as defined in claim I, wherein said sleeve is of a tubular configuration and said core is formed with a periphery of circular cross section and is provided with a plurality of longitudinally extending grooves disposed at circumferentially spaced intervals therearound and extending radially inwardly of the periphery toward the center of said core.

6. The work-supporting device as defined in claim 3, wherein said contact means comprises a shoe of a conductive material affixed in electrical contact on each end portion of said bar and adapted to slidably contact a source of electrical energy when the work-supporting device is positioned at a work station.

7. The work-supporting device as defined in claim 4, wherein the tubular said core is formed with a circular core extending longitudinally through substantially the center thereof tor substantially the entire length of said bar.

8. The work-supporting device as defined in claim 5, wherein said grooves are of a radially outwardly divergent substantially V-shaped cross section.

9. The work-supporting device as defined in claim 8, wherein said grooves are of a substantially rectangular crosssectional shape. 

2. The work-supporting device as defined in claim 1, further including engaging means on said frame adapted to be engaged for supporting and transporting said device between work stations.
 3. The work-supporting device as defined in claim 1, further including contact means on said frame electrically connected to said bar and adapted to be disposed in electrical contact with a source of electrical energy at a work station.
 4. The work-supporting device as defined in claim 1, wherein said bar is of a substantially circular cross section and wherein said sleeve and said core are of a tubular configuration.
 5. The work-supporting device as defined in claim 1, wherein said sleeve is of a tubular configuration and said core is formed with a periphery of circular cross section and is provided with a plurality of longitudinally extending grooves disposed at circumferentially spaced intervals therearound and extending radially inwardly of the periphery toward the center of said core.
 6. The work-supporting device as defined in claim 3, wherein said contact means comprises a shoe of a conductive material affixed in electrical contact on each end portiOn of said bar and adapted to slidably contact a source of electrical energy when the work-supporting device is positioned at a work station.
 7. The work-supporting device as defined in claim 4, wherein the tubular said core is formed with a circular core extending longitudinally through substantially the center thereof tor substantially the entire length of said bar.
 8. The work-supporting device as defined in claim 5, wherein said grooves are of a radially outwardly divergent substantially V-shaped cross section.
 9. The work-supporting device as defined in claim 8, wherein said grooves are of a substantially rectangular cross-sectional shape. 